mm, compaction: encapsulate resetting cached scanner positions

Reseting the cached compaction scanner positions is now open-coded in
__reset_isolation_suitable() and compact_finished().  Encapsulate the
functionality in a new function reset_cached_positions().

Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 10 insertions, 6 deletions

diff --git a/mm/compaction.c b/mm/compaction.c
index 2c1e1ff321bf..0dce7e87d771 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -207,6 +207,13 @@ static inline bool isolation_suitable(struct compact_control *cc,
         return !get_pageblock_skip(page);
 }
 
+static void reset_cached_positions(struct zone *zone)
+{
+        zone->compact_cached_migrate_pfn[0] = zone->zone_start_pfn;
+        zone->compact_cached_migrate_pfn[1] = zone->zone_start_pfn;
+        zone->compact_cached_free_pfn = zone_end_pfn(zone);
+}
+
 /*
  * This function is called to clear all cached information on pageblocks that
  * should be skipped for page isolation when the migrate and free page scanner
@@ -218,9 +225,6 @@ static void __reset_isolation_suitable(struct zone *zone)
         unsigned long end_pfn = zone_end_pfn(zone);
         unsigned long pfn;
 
-        zone->compact_cached_migrate_pfn[0] = start_pfn;
-        zone->compact_cached_migrate_pfn[1] = start_pfn;
-        zone->compact_cached_free_pfn = end_pfn;
         zone->compact_blockskip_flush = false;
 
         /* Walk the zone and mark every pageblock as suitable for isolation */
@@ -238,6 +242,8 @@ static void __reset_isolation_suitable(struct zone *zone)
 
                 clear_pageblock_skip(page);
         }
+
+        reset_cached_positions(zone);
 }
 
 void reset_isolation_suitable(pg_data_t *pgdat)
@@ -1160,9 +1166,7 @@ static int __compact_finished(struct zone *zone, struct compact_control *cc,
         /* Compaction run completes if the migrate and free scanner meet */
         if (compact_scanners_met(cc)) {
                 /* Let the next compaction start anew. */
-                zone->compact_cached_migrate_pfn[0] = zone->zone_start_pfn;
-                zone->compact_cached_migrate_pfn[1] = zone->zone_start_pfn;
-                zone->compact_cached_free_pfn = zone_end_pfn(zone);
+                reset_cached_positions(zone);
 
                 /*
                  * Mark that the PG_migrate_skip information should be cleared